The practice of dispensing heavy and particulate materials through traditional aerosol spray can valve assemblies in the aerosol industry has presented problems in which the heavy and particulate materials to be dispensed clog up the valve assemblies. These heavy and particulate materials may include exterior stucco, heavy sand finishes, drywall and acoustic ceiling patching materials, fire suppressant materials, adhesive and bonding materials, and even culinary sauces.
A traditional aerosol spray can may be filled with these heavy and particulate materials for spraying. In the traditional aerosol spray can, the material to be dispensed must pass through an orifice that is normally sealed off (with a seal or gasket, e.g.) in the unactuated position. When the actuator is depressed, the orifice is exposed to allow the material to pass through. However, when heavy and particulate materials are used, they tend to clog up the valve assemblies (e.g., by clogging up or sticking to the seal, the orifice, and/or the area therebetween) and render the aerosol spray cans inoperative. Constant operation of these aerosol spray cans in spraying heavy and particulate materials is not possible due to inconsistent ability of these traditional valve assemblies to dispense these materials without clogging.
U.S. Pat. No. 5,715,975, issued to Stern et al., discloses an aerosol spray texturing device that is comprised of a container, a nozzle, a valve assembly, and an outlet. The valve assembly in the '975 patent is located in the upper section of the container near the nozzle. Although the nozzle tube of the device in the '975 patent may be configured to spray texture materials, the device in the '975 patent still has the problem of clogging or packing of the valve assembly by the particulates contained in the texture material for spraying, especially if the particulates are large, like those found in stucco or other heavy and particulate materials mentioned above.
U.S. Pat. No. 5,037,011, issued to the present Applicant, discloses a spray apparatus for spraying a texture material through a nozzle. In this apparatus as well there exists a problem of spraying texture materials having large particulates, such as stucco, because the particulates also clog up the valve opening within the spray apparatus.
Therefore, a long-standing need has existed to provide an apparatus that may be used to readily apply heavy and particulate materials in aerosol form, such as exterior stucco, heavy sand finishes, drywall and acoustic ceiling patching materials, fire suppressant materials, adhesive and bonding materials, and culinary sauces. Furthermore, the heavy and particulate materials to be applied should be contained in a hand-held applicator so that the materials may be conveniently stored, as well as dispensed, in a simple and convenient manner without clogging or packing the valve assembly of the applicator.
An object of the present invention, therefore, is to provide a valve assembly for use in an aerosol spray can capable of spraying viscous materials or materials with large particulates without clogging or packing like traditional aerosol spray cans designed for spraying texture materials.
Another object of the present invention is to provide an inexpensive and economical means for matching surface texture of a repaired or patched surface area on a drywall panel, acoustic ceiling, or stucco-covered surface.
Another object of the present invention is to improve the appearance of patched or repaired areas on a textured surface by employing a spray-on hardenable texture material that covers the repaired or patched area and visually assumes the surface texture of the surrounding patched or repaired surface.
Another object of the present invention is to provide a hand-held dispensing unit containing a pressurized texture surface material for spray-on and direct application of the material in a liquid or semi-liquid form onto a repaired or patched area so that the surrounding patched or repaired surface will be visually and mechanically matched.
Another object of the present invention is to provide a valve assembly for use in an aerosol spray can capable of spraying highly-viscous materials, such as fire suppressant materials, adhesive and bonding materials, and culinary sauces, as well as colored agents, resins, catalysts, blowing agent, urethane-type products, and the like, including the ability to spray two different materials from a single can, without clogging or packing like traditional aerosol spray cans when spraying these materials.
One embodiment of the valve assembly comprises a dip tube disposed inside a container. A rod is disposed inside the dip tube so that it may move lengthwise within the dip tube. A sealing member is coupled to the bottom end of the rod, so as to form a tight-seal with the bottom opening of the dip tube when the rod is in an up position, and it exposes the bottom opening of the dip tube to the heavy and particulate material inside the container when the rod is in a down position. A bushing is also coupled to the top opening of the dip tube. Finally, an actuator is coupled to the top end of the rod and the bushing, allowing the user to depress the actuator, thus lowering the rod to its down position and exposing the bottom opening of the dip tube to the material within the container, and allowing the heavy and particulate material to move up the dip tube and out of the container.
Another embodiment of the valve assembly comprises a dip tube disposed inside the container. An interior tube is disposed inside the dip tube so that it may move lengthwise within the dip tube. There is at least one orifice at the bottom end of the interior tube. A top O-ring is coupled to the interior tube adjacent the at least one orifice to prevent any bypass of the heavy and particulate material into the dip tube, and a bottom O-ring is coupled to the bottom end of the interior tube to seal off the valve assembly when not actuated. The top opening of the dip tube is coupled to a bushing. Finally, an actuator is coupled to the top end of the interior tube, allowing the user to depress on the actuator, thus lowering the interior tube to its down position and exposing the at least one orifice on the interior tube to the material inside the container and allowing the heavy and particulate material to flow up the interior tube and out of the container.
In yet another embodiment of the invention, a valve assembly is described wherein the valve opening may be located at substantially any point between the bottom and of the top of the container. The valve assembly includes a side-fitting dip tube and a side-feeding mechanism, whereby texture material is dispensed when a central channel is aligned with a side conduit that is in flow communication with the dip tube. The valve assembly also includes a guiding mechanism to ensure alignment of the central channel and the side conduit in the actuated position. The embodiment just described provides for a much simpler and faster assembly, as well as a reduction in the amount of gas that is lost. In addition, placement of the dip tube on the side (within the container) eliminates the need to build different sizes of valve assemblies to fit a range of container sizes. Thus, a single size of the valve assembly may be produced and dip tubes of various lengths may be used to fit the intended container size. As such, this embodiment also provides a reduction in size and costs associated with the use of multiple container sizes.
In another embodiment of the invention, the valve assembly described immediately above includes two or more side-fitting dip tubes, wherein one of the tubes extends towards the bottom of the container and is in direct contact with the material housed within the container (as described above). Each one of the one or more additional dip tubes, on the other hand, is connected to a storage member, such as a sack or a pouch, which, in turn, is housed within the container. In this way, when the actuating mechanism is activated, a first material (or fraction of material) is drawn through the first dip tube, and a second material (or second fraction of the same material) is drawn through the second dip tube, thereby allowing two different materials (or fractions of material) to be sprayed from a single container. When more than two dip tubes are present, the aerosol container may be used to spray as many different materials (or fractions of materials) from a single container as there are dip tubes by connecting each additional dip tube to a separate storage member within the container.
The invention prevents clogging or packing of the valve assembly by eliminating the need for a seal or gasket which, as was described above, is required in traditional aerosol spray cans. However, the elimination of the gasket, without more, would simply allow the contents near the top the container to leave. That is, provisions must be made to ensure that the entire contents of the container can be dispensed. To this end, in embodiments of the present invention, the valve opening may be at the bottom of the container, as opposed to being at the top, as in traditional aerosol spray cans. In other embodiments, the valve assembly may still be placed near the top of the container, with a dip tube that receives sprayable material from the bottom of the container and feeds the material through a side conduit and an angled channel. The placement of the valve opening as described with respect to the embodiments herein greatly reduces the clogging or packing of the valve by texture materials having large particulates. This improvement allows the efficient and low-cost spraying of more highly-textured materials, because there is no longer the problem of clogging or packing of the valve opening by the particulates suspended within the textured material.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings that illustrate, by way of example, various features and embodiments of the invention.